The Most Dangerous Rocket Fuels Ever Tested

hello its scott manley here and today i am finally in possession of my copy of ignition and informal history of liquid rocket propellants by john d clark a book written in 1972 just before I was born but its reputation amongst fans of rockets is a somewhat special it is a basically a book on chemistry under the chemistry of rocket fuels it covers a you know post-war period up to the early late 60s and it is written in a very amusing style very a lot of jokes and stuff it's kind of a bit like Hunter s Thompson but with a different completely different kind of chemistry this book was out of print for a really long time during which it wasn't uncommon to see copies selling for hundreds of dollars but in the meantime its stature has grown and many people have wanted a reprint and finally Rutgers University has reprinted this so I can pick up my copy I got this from Barnes & Noble because Amazon was sold out they weren't gonna be able to ship new ones until late in June so I'm I'm quite happy to see that people are really buying it then oh yeah I've previously talked about the chemistry of rocket fuel most recently I actually talked about the fuel that von Braun used in the v2 ethanol a rocket fuel that wasn't just safe enough to drink but that the powers-that-be went to great lengths to try and stop people from drinking it because it was basically very strong vodka now if you look inside the pages of this book you're gonna hear about some vastly more toxic rocket fuels I mean we've talked in the past about hydrazine the various derivatives of that we've used today that you know hits the human nervous system not to mention being carcinogenic and highly corrosive hydrazine based fuels are ubiquitous in reaction control systems where you need storable propellants for a long period of times and they're still used in the first-stage boosters of some russian and chinese launch vehicles the combination of unsymmetrical dimethyl hydrazine and nitric acid was nicknamed by the soviets as the devil's venom and this was the fuel that was used in our 16 ICBM which famously are less famously exploited during testing killing many of the engineers and chief marshal nedelin known as the nedelin disaster but for all its toxicity hydrazine is still in use because its drawbacks are tolerated but there have been other fuels with many more extreme properties that have been investigated only to be carefully set aside because the advantages weren't quite as promising or the drawbacks were just too big for example the author talks about ozone now ozone is a molecule which is made of oxygen atoms that the garden-variety oxygen that we breathe and needs to survive has two oxygen atoms but ozone has a third so you get 50% more oxygen right well actually it's even better than that the density is almost double that of regular liquid oxygen when you have liquid ozone but that third OH oxygen atom makes a molecule kind of unstable it really wants to get out of there and releases energy in the process so these monatomic oxygen atoms coming off those are desperate to bind to anything if you happen to be a biological organism nearby it's quite likely that that oxygen atoms will come off and bind to some inconvenient part of your cellular biology and cause all sorts of problems that's why liquid that's why ozone is used in some you know sterilization and purification systems because it's actually really toxic at a cellular level it's also unstable as I've mentioned and it has a propensity for exploding if you have pure liquid ozone since the pure ozone was so lethal experimenters would use mixtures of liquid ozone and oxygen in our three to one oxygen two also and ratio B even then after they successfully ran their engines they would later find out they would find the engines would explored after they were shut down but the author ends the section on cryogenics with a nice little word about ozone and its potential future prospects back in 1972 for ozone still explodes some investigators believe that the explosions are initiated by traces of organic pearl site and this stuff which come from traces of oil the oxygen was made of other workers are convinced that it's just the nature of also and to explode and still others are sure that original sin has something to do with it so although ozone research has been continuing in a desultory fashion there are very few true believers left who are still convinced that ozone will someday somehow come into its own I'm not one of them the same chapter on cryogenics also talks about liquid fluorine which is a stronger more energetic oxidizer than liquid oxygen pairing hydrogen with fluorine instead of oxygen results in a boost in performance but it also results in an exhaust of hydrofluoric acid which is nasty stuff both the oxidizer and the exhaust are horribly toxic there's no way a booster would ever be fueled this way but there is a niche for upper stages where they always rocket is far enough down range that the exhausts would be well enough to disperse before returning to earth but I don't see that happening hydrofluoric acid poisoning is nasty because the hydrofluoric acid gets absorbed through your skin and once in sight it starts looking for calcium ions and it peels it out of your bones or in various other chemicals that are perhaps used for nerve signaling the way you treat it is by you overdosing the person with huge amounts of calcium and people have been known to survive just fine but it is not nice but anyway if liquid fluorine wasn't a reactive enough how about you try to put even more fluorine into the system chlorine trifluoride where there are three fluorine atoms that have been persuaded to huddle around a single chlorine atom and they're just ready to get out of there and react with something else as an aside a lots of these adventures and fluorine chemistry were in fact a byproduct of the Manhattan Project which of course used things like uranium hexafluoride and fuel enrichment I'll let the author explain just how potent chlorine trifluoride is it is of course extremely toxic but that's the least of the problem it is hypergolic with every known fuel and so rapidly hypergolic that no ignition delay has ever been measured it is also hypergolic with such things as cloth wood and test engineers not to mention asbestos sand and water with which it reacts explosively it can be kept in some of the ordinary structural metals steel copper aluminum etc because of the formation of a thin film of all insoluble metal fluoride which protects the bulk of the metal just as the invisible Court of Al Aqsa Don aluminium keeps it from burning up in the atmosphere if however this coat is melted or scrubbed off and has no chance to reform the operator is confronted with the problem of coping with a metal fluorine fire for dealing with this situation I've always recommended a good pair of running shoes the truth is it was just too corrosive making the engineering problems of utilizing it safely the real barrier to actual use incidentally the highest specific impulse ever obtained from a chemical rocket engine was a lithium fluorine hydrogen engine the Tri propellant design required cryogenic storage of the fluorine and hydrogen while the lithium had to be heated to keep it liquid all this engineering effort yielded a specific impulse of 542 seconds which was a significant improvement over the 450 seconds that you get from the space shuttles main engines the pursuit of performance wasn't always about specific impulse though hydrogen's high performance is offset by low density and in many military applications the density is more desirable one section on the pursuit of higher densities discusses the use of mercury in rocket fuels the first suggestion was dimethyl mercury a substance whose toxicity is legendary it famously killed a scientist researching the stuff after a drop of it was absorbed through her latex gloves and then through her skin jay chapter 12 when the book talks about mercury and rocket fuels I looked the stuff up and discovered that indeed the synthesis was easy but that it was extremely toxic and a long way from harmless as I had suffered from mercury poisoning on two previous occasions and didn't care to take a chance doing it again I thought it would be an excellent idea to have somebody else make the compound for me so I phoned Rochester and asked my contact Eastman Kodak if they would make a hundred pounds of dimethylmercury and ship it to me I heard horrified gasp and then a tightly controlled voice I could hear the grinding of teeth behind in the words inform me that if they were silly enough to synthesize that much dimethylmercury they would in the process fog every square inch of photographic film in Rochester and that thank you just the same Eastman was not interested the receiver came down with a crash and I sat back to consider the matter an agonizing reappraisal seemed to be indicated so indeed a reappraisal was indicated that wouldn't be the end of the project instead the author proposed injecting regular mercury into a combustion chamber of another rocket fully expecting that such a crazy plan would be rejected instead they were given the go-ahead and they actually started building a whole complex test setup with a scrubbing system to make sure that the mercury would be removed but their project was shut down and it was moved to a different lab who then successfully tested this out in the middle of the desert hopefully not poisoning anything worse than rattlesnakes thankfully injecting mercury into rocket exhausts never went anywhere beyond this test anyway the book is amazing and I highly recommend it to anyone that's interested in rockets chemistry or is just interested in a fun book on science the title is ignition and informal history of liquid rocket propellant by jointiy Clarke has a foreword by Isaac Asimov as well but yet it's it's fun it's a also in demand so be aware that if you order it right now it may take a little longer than usual to get there but yeah so glad they reprinted this I'm Scott Manley fly safe [Music] [Music]

Channel: Scott Manley

Views: 342,927

Rating: 4.9479361 out of 5

Keywords: science, rocket, chemistry, ignition, rocket science, fluorine, chlorine trifluoride, ozone, mercury

Id: _wLk2j7_KB0

Length: 11min 5sec (665 seconds)

Published: Tue May 29 2018